Preparation process for semiconductor device

ABSTRACT

According to this invention, residues generated after selectively removing a low-dielectric-constant film such as SiOC can be effectively removed without damage on an insulating film or metal film. Specifically, residues  126  and  128  generated after forming an interconnect trench in an SiOC film  116  are removed using a fluoride-free weak alkaline amine stripper. After the removing step, the wafer is rinsed with isopropyl alcohol and then dried without drying with pure water.

[0001] This application is based on Japanese patent application NO.2002-201901, the content of which is incorporated hereinto by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a technique for removing a residuegenerated by, for example, etching in a process for preparing asemiconductor device comprising a low-dielectric-constant film.

[0004] 2. Description of the Related Art

[0005] Recently, in response to requirement for operation of asemiconductor device at a higher speed, a copper with a lower resistancehas been used as an interconnection material while in the light ofreducing a parasitic capacitance between interconnections, a so-calledlow-dielectric-constant film has been employed as an interlayerinsulating film material. The term “low-dielectric-constant film” refersto a film made of a material having a lower dielectric constant thanSiO₂, generally a film with a specific dielectric constant of 4 or less.

[0006] There have been intense attempts for developing utilities of afilm formed by an application process such as HSQ (hydrogensilsesqueoxane) or MSQ (methyl silsesqueoxane) as alow-dielectric-constant film as described above. However, for such afilm, the film may be partially dissolved due to moisture absorptionduring a semiconductor process, or a stress may be generated in the filmby heating, leading to, defective interlayer adhesiveness.

[0007] Thus, there have been conducted intense application studies for alow-dielectric-constant film formed by CVD. Among others, SiOC exhibitsa relatively stable specific dielectric constant (about 2.8) even aftera high-temperature process, and is therefore promising as an interlayerinsulating film material for a semiconductor device comprising copperinterconnections.

SUMMARY OF THE INVENTION

[0008] We, however, have found that when using SiOC as an interlayerinsulating film material, various phenomena which have not known in aconventional insulating film material. For example, in a semiconductorprocess comprising the sequential steps of:

[0009] (i) forming a copper film on a semiconductor substrate, on whichis then formed an SiOC film;

[0010] (ii) forming a resist on the SiOC film and using the resist as amask to form a hole by dry etching to expose a copper film surface;

[0011] (iii) removing the resist by ashing;

[0012] (iv) cleaning the inside of the hole with a stripper; and

[0013] (v) rinsing the product,

[0014] the side wall of,the hole may be etched during the step (iv) sothat a desired shape cannot been formed. Furthermore, during rinsingwith pure water during the step (v), a part of the copper film may bedissolved or in extreme cases, an abrupt reaction in the copper surfacemay form a dendrite extrusion.

[0015] Thus, an object of this invention is to provide a techniquewhereby a residue generated during selectively removing alow-dielectric-constant film made of, for example SiOC can beeffectively removed without any problem described above or damage on theinsulating film or metal film.

[0016] This invention which can solve the above problems provides aprocess for manufacturing a semiconductor device comprising the steps offorming an SiOC-containing insulating film on a semiconductor substrate,and then selectively removing the insulating film; and removing theresidue generated during the previous step with a fluoride-free weakalkaline stripper.

[0017] This invention also provides a process for manufacturing asemiconductor device comprising the steps of forming an insulating filmhaving a specific dielectric of 4 or less on a semiconductor substrateby CVD or sputtering, and then selectively removing the insulating film;and removing the residue generated during the previous step with afluoride-free weak alkaline stripper. The insulating film may comprisesilicon and carbon as constituent elements.

[0018] According to the above manufacturing process, a fluoride-freeweak alkaline stripper is used. Thus, the residue generated duringselective removal of the insulating film can be effectively removedwithout damage on the insulating film. If the stripper contains fluorideions, the insulating film may be often damaged. Furthermore, if thestripper is strong alkaline or acidic, it is difficult to effectivelyremove the residue without damage on the insulating film.

[0019] This invention also provides a process for manufacturing asemiconductor device comprising the steps of forming a copper-containingmetal film and then an SiOC-containing insulating film on asemiconductor substrate; selectively removing the insulating film toform a concave such that a part of the copper-containing film isexposed; and removing a residue generated during selective removal ofthe insulating film with a fluoride-free weak alkaline stripper.

[0020] This invention also provides a process for manufacturing asemiconductor device comprising the steps of forming a copper-containingmetal film on a semiconductor substrate and then an insulating filmhaving a specific dielectric constant of 4 or less by CVD or sputtering;selectively removing the insulating film to form a concave such that apart of the copper-containing film is exposed; and removing a residuegenerated during selective removal of the insulating film with afluoride-free weak alkaline stripper.

[0021] According to the above manufacturing process, a fluoride-freeweak alkaline stripper is used. Thus, the residue generated duringselective removal of the insulating film can be effectively removedwithout damage on the insulating film and the copper-containing metalfilm. If the stripper contains fluoride ions, the insulating film may beoften damaged. Furthermore, if the stripper is strong alkaline oracidic, it is difficult to effectively remove the residue without damageon the insulating film. In the manufacturing process, a“copper-containing film” refers to a copper film or a film containingcopper as a major component. In addition to copper, other metals such asSn, Al, Ti, Ag, Ni and Mg may be contained as minor components.

[0022] The step of selectively removing the insulating film in thisinvention may comprise forming a resist having an opening on theinsulating film; selectively removing the insulating film using theresist as a mask; and then removing at least part of the resist byashing. Although a hole or trench may be formed in the insulating filmin a well-controlled manner by employing such a process, ashing may leadto a damaged part, which may be then side-etched during the subsequentstripper treatment, and thus a hole or trench having a desired shapecannot be formed. In this regard, this invention employs a fluoride-freeweak alkaline stripper during removal of the residue. Therefore, adamaged part due to ashing is little etched by a stripper, resulting ina hole or trench as originally designed.

[0023] The process for manufacturing a semiconductor device according tothis invention may further comprise a step of rinsing the product usinga non-aqueous rinse agent alone after the above step of removing theresidue. After removing the residue with a stripper, rinsing isconducted usually for washing the stripper out. The rinsing step hasbeen generally conducted with pure water when using a hydrofluoric acidstripper while being conducted with IPA and then with pure water whenusing a strong alkaline stripper. We have, however, found afterinvestigation that

[0024] (i) a strong alkaline stripper may cause side etching of adamaged part generated by, for example, ashing; and that

[0025] (ii) a hydrofluoric acid stripper may dissolve a part of a copperfilm during rinsing with pure water required for washing the stripperout, or in extreme cases, form a dendrite extrusion on the coppersurface. The above (i) will be later described in Examples. Thus, thephenomenon of the above (ii) will be described below.

[0026] Our studies have indicated that, for example, when thecopper-containing metal film and the SiOC film both of which are exposedare in contact with water, it tends to cause the dissolution of thecopper film from the surface or the forming of a dendrite. It isprobably because electric charge accumulated in, for example, the SiOCfilm during the semiconductor process interacts with water. Such aphenomenon becomes marked when a copper-containing metal film is buriedin an insulating film so that there are no leak paths for electriccharge to the outside, or when the surface of the copper-containing filmexposed in a hole bottom may be in contact with water.

[0027] For preventing dissolution of a copper film or generation of adendrite, it is desirable to conduct rinsing without water. However, inrinsing without water, remaining of the stripper becomes significant.This invention, therefore, employs a fluoride-free weak alkalinestripper. It may effectively prevent remaining of the stripper afterrinsing. That is, this invention can prevent production problems such asdissolution of a copper film or dendrite formation while preventingremaining of a stripper after rinsing.

[0028] A stripper in this invention may preferably have pH within arange of more than 7 and 11 or less, resulting in prevention ofdissolution of a modified part in an insulating film by the stripper,dissolution of the copper film or dendrite formation. Furthermore, evenwhen only a non-aqueous rinsing agent is used for rinsing, remaining orprecipitation of the stripper after rinsing can be minimized.

[0029] This invention is more effective when an insulating filmcomprises SiOC. SiOC exhibits a relatively stable specific dielectricconstant (about 2.8) even after a high-temperature process. It may,however, be damaged by a stripper or when being used in combination witha copper film, may cause dissolution of the copper film or generation ofa dendrite. In this invention, such problems can be solved so thatexcellent advantages of SiOC may be effectively utilized. The term“insulating film comprising SiOC” as used herein encompasses bothinsulating films consisting of SiOC and partially comprising an SiOCstructure.

[0030] This summary of the invention does not necessarily describe allnecessary features so that the invention may also be a sub-combinationof these described features.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIG. 1A shows an example of an interconnection structure obtainedby a process for manufacturing a semiconductor device according to thisinvention.

[0032]FIG. 1B shows an example of an interconnection structure obtainedby a process for manufacturing a semiconductor device according to thisinvention.

[0033]FIG. 2A is a process cross section illustrating a process formanufacturing a semiconductor device according to this invention.

[0034]FIG. 2B is a process cross section illustrating a process formanufacturing a semiconductor device according to this invention.

[0035]FIG. 2C is a process cross section illustrating a process formanufacturing a semiconductor device according to this invention.

[0036]FIG. 3A is a process cross section illustrating a process formanufacturing a semiconductor device according to this invention.

[0037]FIG. 3B is a process cross section illustrating a process formanufacturing a semiconductor device according to this invention.

[0038]FIG. 3C is a process cross section illustrating a process formanufacturing a semiconductor device according to this invention.

[0039]FIG. 4A is a process cross section illustrating a process formanufacturing a semiconductor device using a hydrofluoric acid stripper.

[0040]FIG. 4B is a process cross section illustrating a process formanufacturing a semiconductor device using a hydrofluoric acid stripper.

[0041]FIG. 5 is a flow diagram illustrating a process for manufacturinga semiconductor device according to this invention.

[0042]FIG. 6 is a flow diagram illustrating a process for manufacturinga semiconductor device using a hydrofluoric acid stripper.

[0043]FIG. 7 shows the results of contamination analysis for a copperfilm surface by XPS in Example 2.

[0044]FIG. 8 shows the results of counting particles adhering to a waferafter rinsing in Example 1.

[0045]FIG. 9 illustrates a measurement model for a chain resistanceevaluated in Example 3.

[0046]FIG. 10 shows the measurement results for a chain resistance inExample 3.

[0047]FIG. 11A shows a procedure for preparing a sample in Example 2.

[0048]FIG. 11B shows a procedure for preparing a sample in Example 2.

[0049]FIG. 11C shows a procedure for preparing a sample in Example 2.

[0050]FIG. 12A shows a procedure for preparing a sample in Example 2.

[0051]FIG. 12B shows a procedure for preparing a sample in Example 2.

[0052]FIG. 13 shows the SEM observation results for a copper filmsurface in Example 2.

DETAILED DESCRIPTION OF THE INVENTION

[0053] The invention will now be described based on the preferredembodiments. This does not intend to limit the scope of the presentinvention, but exemplify the invention.

[0054]FIG. 5 shows a specific procedure of a manufacturing process for asemiconductor device according to this invention. First, on asemiconductor substrate are deposited an etching inhibiting film and aninterlayer insulating film, on which is formed a resist with a givenpattern. Using the resist as a mask, the interlayer insulating film isdry-etched to form an interconnect trench (S101). Then, the resist isremoved by ashing (S102), and the etching inhibiting film on the bottomof the interconnect trench is removed by dry etching (S103). Then, theinside of the interconnect trench is treated with a fluoride-free weakalkaline stripper containing a removing ingredient (S104). The wafer isrinsed with IPA (isopropyl alcohol) (S105), and is then dried withoutrinsing with pure water (S106). An embodiment of a manufacturing processfor a semiconductor device comprising such a procedure will be describedwith reference to process cross sections.

[0055]FIG. 1A schematically shows a multi-layer interconnectionstructure where an upper copper interconnection 114 is formed on a lowercopper interconnection 102, and the lower copper interconnection 102 isconnected with the upper copper interconnection 114 through a via plug112. FIG. 1B is a cross section of the multi-layer interconnection inFIG. 1A from the direction indicated by an arrow. As shown in FIG. 1B,an SiOC film 100, an SiO₂ film 104, an SiCN film 106, an SiOC film 108and an SiO₂ film 110 are sequentially formed. The lower copperinterconnection 102 is formed in a multilayered film, consisting of theSiOC film 100 and the SiO₂ film 104 while the via plug 112 is formed ina multilayered film consisting of the SiCN film 106, the SiOC film 108and the SiO₂ film 110. Furthermore, the copper interconnection 114 isformed such that it is connected with the upper surface of the via plug112. There will be described an embodiment where a process according tothis invention is applied to formation of the part above the via plug112 in this interconnection structure.

[0056] In FIGS. 2A to 3B, the left and the right sides show a plug(viaplug 112)-forming part and a non-plug-forming part, respectively.Specifically, the left side shows a cross section of a part of the uppercopper interconnection 114 in FIG. 1A which is in contact with the viaplug 112, while the right side shows a cross section of a part of theupper copper interconnection 114 which is not in contact with the viaplug 112.

[0057] First, as shown in FIG. 2A, on the semiconductor substrate areformed the SiOC film 108 and the SiO₂ film 110. In the multilayered filmis formed a via plug 112, and then on the surface are sequentiallydeposited an SiCN film 113, an SiOC film 116 and an SiO₂ film 118.

[0058] Then, on the SiO₂ film 118 is formed a resist 120 with a givenopening. Using the resist as a mask, the SiOC film 116 is dry-etched toform an interconnect trench 122 (FIG. 2B). In the non-plug-forming partin FIG. 2B, the SiCN film 113 and the SiO₂ film 110 are partially openedand thus the SiOC film 108 is exposed. It is because during the step offorming the interconnect trench 122, the film is overetched so thatopenings are formed in parts of the SiCN film 113 and the SiO₂ film 110.

[0059] Then, ashing by oxygen plasma is conducted to remove the resist120 (FIG. 2C). In this process, the SiOC film 116 and the SiOC film 108exposed in the interconnect trench is modified to generate a modifiedlayer 124. Although the mechanism whereby the modified 124 is formed isnot clearly understood, it would be caused by reaction of O (oxygen) inoxygen plasma with C in SiOC.

[0060] Then, the SiCN film 113 in the bottom of the interconnect trenchis removed by dry etching (FIG. 3A) to expose the upper surface of thevia plug 112 in the bottom of the interconnect trench. This etchingallows residues 126 and 128 to adhere to the inside of the interconnecttrench. Treatment with a stripper is conducted for removing theseresidues. In this embodiment, fluoride-free weak alkaline amine stripperis used. An “amine stripper” is a stripper containing an amine compoundhaving an amino group as an essential component and a solvent used maybe water or a hydrophilic solvent. The stripper may contain ananticorrosive as appropriate. In this embodiment, such a stripper may beused to prevent side etching of SiOC in the trench and to significantlyreduce residues during a subsequent rinsing process.

[0061] In contrast, when using a solution containing ammonium fluorideinstead of the above amine stripper, side etching proceeds in aninterconnect trench during dry etching for forming the trench so that aninterconnect trench having a desired shape may not be formed. FIG. 4Aand FIG. 4B show such the situation. When the wafer is treated with thesolution containing ammonium fluoride as a stripper in the step shown inFIG. 4A, the modified layer 124 is dissolved in the stripper. As aresult, side etching of the SiOC film 116 shown in FIG. 4B proceeds sothat an interconnect trench having designed dimensions cannot be formed.Although the mechanism whereby the stripper dissolves the modified layer124 is not clearly understood, the modified layer 124 may be probablyconverted to have a structure similar to SiO_(x).

[0062] Again referring to FIG. 3A, the above treatment for removing theresidues in the interconnect trench gives the state as shown in FIG. 3B.Then, a copper film is formed by a damascene process such that it fillsthe interconnect trench, and the excessive copper film outside thetrench is removed to form an upper copper interconnection 114 (FIG. 3C).Thus, a copper multilayer interconnection structure is provided.

[0063] In the above manufacturing process, both upper copperinterconnection 114 and via plug 112 are films comprising copper as amain component and can be formed by any of various deposition methodssuch as plating, CVD, and sputtering. These films may contain, inaddition to copper, Sn, Al, Ti, Ag, Ni and Mg as appropriate.

[0064] In the above manufacturing process, the SiOC film may bedeposited by, for example, CVD or sputtering.

[0065] In the above manufacturing process, the SiCN film 113 acts as anetching inhibiting film when forming the interconnect trench as well asprevents components such as copper from diffusing from the via plug 112.Although SiCN is used herein, another material such as SiC, SiN and SiONmay be used.

[0066] Although being unshown and not described in FIGS. 2A to 3B, thesides and the bottoms of the upper copper interconnection 114 and of thevia plug 112 are coated with a barrier metal film. The barrier metalfilm may be made of a material containing a high melting metal such asTi, TiN, W, WN, Ta and TaN, or alternatively may be a multilayer film inwhich layers of two or more of these metals are layered. The barriermetal film may be formed by an appropriate technique such as sputteringand CVD.

EXAMPLES Example 1

[0067] In this example, an SiOC film deposited on a copper film wasdry-etched to form a hole reaching the copper film, the inside of thehole was washed with a given stripper, and then cleaning performance forcontaminants and damage on the film were evaluated.

[0068] (i) Sample Preparation

[0069] The processes illustrated in FIGS. 2A to 3B were conducted toprepare a sample. Specifically, in a copper film was formed aninterconnect trench, residues dry etching were removed and the productwas rinsed to give a sample. The copper film was deposited by plating.SiOC film was formed by CVD.

[0070] The following strippers (NOs. 1 to 4) were used.

[0071] Stripper NOs. 1 and 2 comprising an amine, an organic solvent,water, an anticorrosive and an organic acid. The organic acid was addedfor adjusting pH;

[0072] Stripper NO. 3 comprising ammonium fluoride, an organic solvent,water, an anticorrosive and an organic acid; and

[0073] Stripper NO. 4 comprising an amine (strong alkali), an organicsolvent, water, an anticorrosive and an organic acid.

[0074] pH values of these strippers as determined by a pH meter areshown in Table 1. Treatment with a stripper was conducted at roomtemperature for 10 min.

[0075] All samples were rinsed with IPA (isopropyl alcohol) alone.

[0076] (ii) Evaluation

[0077] Deposit Removal

[0078] Removal of a deposit within an interconnect trench was evaluatedby SEM observation.

[0079] ⊚: No deposit;

[0080] ◯: Little deposit;

[0081] Δ: A small amount of deposit;

[0082] ×: A large amount of deposit

[0083] Damage on an Insulating Film

[0084] Damage on an insulating film (SiOC film) within an interconnecttrench was evaluated by SEM observation.

[0085] ◯: Little damage;

[0086] Δ: Minor side etching of the SiOC film;

[0087] ×: Significant side etching of the SiOC film.

[0088] Damage on a Copper Film

[0089] Damage on a copper film exposed in the bottom of an interconnecttrench was evaluated by SEM observation.

[0090] ◯: Little damage;

[0091] Δ: Minor damage;

[0092] ×: Significant damage.

[0093] Residues on a Copper Surface After Rinsing

[0094] After rinsing, presence of residues on a copper film was observedby SEM.

[0095] ◯: Little stain after rinsing;

[0096] Δ: Minor stain after rinsing;

[0097] ×: Significant stain after rinsing.

[0098] Adhering Particle Count After Rinsing

[0099] After rinsing, particles remaining within an interconnect trenchare counted under SEM observation.

[0100] (iii) Results

[0101] Table 1 shows the results for these evaluation parameters. FIG. 8shows the results of counting particles adhering to the wafer afterrinsing. These results indicate that a fluoride-free weak alkalinestripper (NOs. 1 and 2) can be used to prevent damage,on the film andresidue formation after rinsing and also to effectively remove etchingresidues. TABLE 1 Stripper NO. NO.1 NO.2 NO.3 NO.4 Stripper pH   8   115-6   12 Fluoride in a Absent Absent Present Absent stripper Removal ofdeposit ⊚ ◯ Δ Δ Damage on a copper ◯ ◯ ◯ ◯ film Damage on an ◯ ◯ X Δinsulating film Residues on a ◯ ◯ X X copper surface after rinsingAdhering particle ≦50 ≦50 150-270 ≦50 count after rinsing (particles perwafer)

Example 2

[0102] In this example, a number of via holes were formed in a siliconwafer and then contamination in the surface of a copper film wasevaluated. A sample preparation procedure in this example will bedescribed with reference to FIGS. 11A to 12B.

[0103] First, as shown in FIG. 11A, on a semiconductor substrate(unshown) were formed an SiOC film 108 and an SiO₂ film 110, and inthese multilayered films was formed a via plug 131 made of copper bydamascene process. Then, on the surface were sequentially deposited anSiCN film 113, an SiOC film 116 and an SiO₂ film 118 by CVD.

[0104] Then, on the SiO₂ film 118 was formed a resist 120 having a givenopening. Using the resist as a mask, the SiO₂ film 118 and the SiOC film116 were dry-etched (FIG. 11B). At the end of etching, ashing by oxygenplasma was conducted to remove the resist 120 (FIG. 11C). During thisprocess, the SiOC film 116 exposed within the interconnect trench wasmodified to form a modified layer 124.

[0105] Then, the SiCN film 113 in the bottom of the hole was removed bydry etching (FIG. 12A). Thus, the upper surface of the via plug 131 wasexposed in the bottom of the hole. This etching allows residues 126 and128 to adhere to the inside of the interconnect trench.

[0106] Then, a stripper was used to remove the residues (FIG. 12B). Twosamples were prepared by using Stripper NOs. 1 and 4 shown in Table 1 asa stripper. After the substrate was rinsed with IPA and dried, thesamples were evaluated.

[0107] The samples thus obtained and a sample prepared omitting strippertreatment and rinsing were observed by SEM and analyzed by XPS (X-rayphotoelectron spectroscopy).

[0108]FIG. 13 shows the SEM observation results. The results indicatethat the sample prepared using Stripper NO. 4 which is strongly alkalinefailed to adequately stripperesidues on the copper film surface. Incontrast, residues on the copper film surface were adequately removed inthe sample prepared using Stripper NO. 1.

[0109]FIG. 7 shows the XPS analysis results for a copper film surface.In the sample prepared using Stripper NO. 4, peaks corresponding tocontaminants such as CuO remain as are in the untreated sample. Thesepeaks probably represent the presence of copper-containing contaminantsadhering to the Cu surface. In contrast, in the sample prepared usingStripper NO. 1, such peaks corresponding to contaminants such as CuOdisappear. These experimental results indicate that a stripper accordingto this invention may be used to significantly reduce copper compoundson a copper film surface.

Comparative Example

[0110] After etching a hole as described in Example 2, residues wereremoved by a stripper containing ammonium fluoride and the substrate wasrinsed with pure water. FIG. 6 shows the sample preparation procedure.First, on a semiconductor substrate were deposited an etching inhibitingfilm made of SiCN and an interlayer insulating film made of SiOC. On thesurface was formed a resist having a given shape. Using the resist as amask, the interlayer insulating film was dry-etched to form a via hole(S501). Then, after removing the resist by ashing (S502), the etchinginhibiting film in the bottom of the via hole was removed by dry etching(S503). Then, the inside of the via hole was treated with a hydrofluoricacid stripper (S504) and rinsed with pure water (S505), and then thewafer was dried (5506).

[0111] After these processes, it was observed that dendrites were formedfrom the copper surface in some of a number of holes formed in thewafer.

Example 3

[0112] A two-layer interconnection structure as shown in FIG. 9 wasprepared as described in Example 1 for an yield test. The wafersprepared using Stripper NOs. 1 and 4 were evaluated.

[0113] The two-layer interconnection structure is known as a via chainconsisting of 500,000 vias and upper and lower interconnections. All ofthe interconnections and the vias are made of copper. Applying a givenvoltage between the ends of the via chain, an electric resistance isdetermined for an interconnection consisting of the interconnections andthe vias. The resistance is referred to as a “chain resistance”. A chainresistance is an effective measure for determining quality of viaconnection. In this example, a via chain described above was formed ineach chip on a silicon wafer and a resistance was determined for eachvia chain. A chip is passed when a measurement is below a standard valuewhile being rejected when a measurement is higher than the standardvalue. A via yield was determined as a proportion of passed chips to thetotal chips.

[0114] The evaluation results are shown in FIG. 10. A via yield littledepended on a pitch and was substantially constant. A sample preparedusing Stripper NO. 1 exhibited a higher yield than that prepared usingStripper NO. 4.

[0115] As described above, according to this invention, residuesgenerated during selectively removing a low-dielectric-constant filmsuch as SiOC are removed using a fluoride-free weak alkaline stripper sothat the residues can be effectively removed without damage on aninsulating film or metal film.

[0116] Although the present invention has been described by way ofexemplary embodiments, it should be understood that many changes andsubstitutions may be made by those skilled in the art without departingfrom the spirit and the scope of the present invention which is definedonly by the appended claims.

What is claimed is:
 1. A process for manufacturing a semiconductor device comprising the steps of: forming an SiOC-containing insulating film on a semiconductor substrate, and then selectively removing the insulating film, and removing the residue generated during the previous step with a fluoride-free weak alkaline stripper.
 2. A process for manufacturing a semiconductor device comprising the steps of: forming an insulating film having a specific dielectric of 4 or less on a semiconductor substrate by CVD or sputtering, and then selectively removing the insulating film, and removing the residue generated during the previous step with a fluoride-free weak alkaline stripper.
 3. The process for manufacturing a semiconductor device as claimed in claim 2 wherein the insulating film comprises silicon and carbon as constituent elements.
 4. The process for manufacturing a semiconductor device as claimed in claim 1 wherein the stripper has pH within a range of more than 7 and 11 or less.
 5. The process for manufacturing a semiconductor device as claimed in claim 2 wherein the stripper has pH within a range of more than 7 and 11 or less.
 6. The process for manufacturing a semiconductor device as claimed in claim 1 wherein the stripper comprises an amine.
 7. The process for manufacturing a semiconductor device as claimed in claim 2 wherein the stripper comprises an amine.
 8. The process for manufacturing a semiconductor device as claimed in claim 1 wherein the step of selectively removing the insulating film comprises forming a resist having an opening on the insulating film, selectively removing the insulating film using the resist as a mask, and then removing at least part of the resist by ashing.
 9. The process for manufacturing a semiconductor device as claimed in claim 2 wherein the step of selectively removing the insulating film comprises forming a resist having an opening on the insulating film, selectively removing the insulating film using the resist as a mask, and then removing at least part of the resist by ashing.
 10. The process for manufacturing a semiconductor device as claimed in claim 1 further comprising a step of rinsing the product using a non-aqueous rinse agent alone after the step of removing the residue.
 11. The process for manufacturing a semiconductor device as claimed in claim 2 further comprising a step of rinsing the product using a non-aqueous rinse agent alone after the step of removing the residue.
 12. A process for manufacturing a semiconductor device comprising the steps of: forming a copper-containing metal film and then an SiOC-containing insulating film on a semiconductor substrate; selectively removing the insulating film to form a concave such that a part of the copper-containing film is exposed; and removing a residue generated during selective removal of the insulating film with a fluoride-free weak alkaline stripper.
 13. A process for manufacturing a semiconductor device comprising the steps of: forming a copper-containing metal film on a semiconductor substrate and then an insulating film having a specific dielectric constant of 4 or less by CVD or sputtering, selectively removing the insulating film to form a concave such that a part of the copper-containing film is exposed, and removing a residue generated during selective removal of the insulating film with a fluoride-free weak alkaline stripper.
 14. The process for manufacturing a semiconductor device as claimed in claim 13 wherein the insulating film comprises silicon and carbon as constituent elements.
 15. The process for manufacturing a semiconductor device as claimed in claim 12 wherein the stripper has pH within a range of more than 7 and 11 or less.
 16. The process for manufacturing a semiconductor device as claimed in claim 13 wherein the stripper has pH within a range of more than 7 and 11 or less.
 17. The process for manufacturing a semiconductor device as claimed in claim 12 wherein the stripper comprises an amine.
 18. The process for manufacturing a semiconductor device as claimed in claim 13 wherein the stripper comprises an amine.
 19. The process for manufacturing a semiconductor device as claimed in claim 12 wherein the step of selectively removing the insulating film comprises forming a resist having an opening on the insulating film, selectively removing the insulating film using the resist as a mask, and then removing at least part of the resist by ashing.
 20. The process for manufacturing a semiconductor device as claimed in claim 13 wherein the step of selectively removing the insulating film comprises forming a resist having an opening on the insulating film, selectively removing the insulating film using the resist as a mask, and then removing at least part of the resist by ashing.
 21. The process for manufacturing a semiconductor device as claimed in claim 12 further comprising a step of rinsing the product using a non-aqueous rinse agent alone after the step of removing the residue.
 22. The process for manufacturing a semiconductor device as claimed in claim 13 further comprising a step of rinsing the product using a non-aqueous rinse agent alone after the step of removing the residue. 